The invention relates to an initialization method for initializing a transfer of a recording image data stream from an image sensor of an image recording apparatus to a display unit, wherein initially a display image data stream is transferred from an image processing apparatus to the display unit and a recording image data stream is transferred from the image recording apparatus to the image processing apparatus, wherein subsequently the display image data stream is changed over to the recording image data stream and the image recorded by the image sensor or the sequence of images is reproduced with the display unit. Preferably, the image recording apparatus is an electronic endoscope having an integrated image sensor. More preferably, the image recording apparatus is a camera head to which an endoscope and/or a probe is/are connectable or connected.
The invention also relates to an image-transferring system having an image processing apparatus and having at least one image recording apparatus with an image sensor. The image-transferring system can be configured in particular as an endoscopy system.
Such initialization methods are known and are used to change over the display image data stream displayed on a display unit, which display image data stream can depict a test image and/or a starting image, for example, to a recording image data stream, which can depict an image or a sequence of images of a scene recorded with the image sensor (that is to say a live image). The image-transferring systems used in this case have an image processing apparatus that is separably connected to an image recording apparatus. There is therefore the possibility of connection of the image recording apparatus to the image processing apparatus resulting in a phase shift between the display image data stream and the recording image data stream. The image recording apparatus is normally supplied with power and/or switched on only upon connection. The resultant phase shift can, however, lead to the display unit changing to a search mode and/or even switching off during the changeover from the display image data stream to the recording image data stream, owing to an absence of signal over too long a phase. This is not desirable, however.
To avoid this switching off and/or the initiation of a search mode on an image data source, it has been proposed that the image sensor and the display unit have a data buffer set up between them that equalizes such a phase offset. This data buffer can be a ring memory in this case, in which the recording image data stream is continually read in and from which the display image data stream to be forwarded to the display unit is continually read out, the phase shift between the two image data streams being able to be matched accordingly. The use of a data buffer has the disadvantage that a time delay occurs in the recording image data stream transfer to the display unit, however. This time delay is all the greater the greater the phase shift between the display image data stream and the recording image data stream. Therefore, there is the possibility of a tolerable and/or permissible time delay being exceeded. Such a time delay can be particularly critical in situations during a medical intervention when for example an endoscopic operation or an examination of a cavity in a patient is performed by a user.